热喷涂涂层界面断裂韧性的反向三点弯曲法试验  

Three-point reverse bending test of interfacial fracture toughness on thermal spraying coating

作　　者：李巧莲[1,2] 张坤[1] 张凯[1,2] 彭青[1,2] 

机构地区：[1]中国科学院力学研究所先进制造工艺力学重点实验室,北京100190 [2]中国科学院研究生院,北京100190

出　　处：《金属热处理》2010年第1期114-116,共3页Heat Treatment of Metals

基　　金：国家自然科学基金面上项目(50471087)

摘　　要：以热喷涂NiCrBSi涂层/钢基体为材料模型,利用将涂层置于受压侧的反向三点弯曲法试验,对热喷涂涂层界面断裂现象进行分析并建立相应的界面断裂韧性计算模型。结果表明,界面裂纹起始于三点弯曲试样中部,对应于加载压头与涂层接触区域正下方的界面上,并向两侧扩展,伴随涂层屈曲,形成分层屈曲的破坏形貌。根据分层屈曲形貌建立计算模型,通过分层屈曲几何参数与屈曲临界应力、涂层内真实应力以及界面断裂韧性的关系,获得界面断裂韧性值。Interfacial fracture phenomenon was analyzed with three-point reverse bending test to measure the interfacial fracture toughness of thermal spraying NiCrBSi coating/steel substrate.The results show that the interfacial crack initiates along the interface under the contact zone of the indenter and the coating at the mid-span,and buckling morphology is formed as the interfacial crack propagates to two ends of the sample.Calculation model is given according the buckling morphology of the coating,and the interfacial toughness is obtained by the relationship between the geometric parameters of coating buckling and critical stress,real stress and interfacial toughness.

关 键 词：三点弯曲试验 热喷涂涂层 分层屈曲 界面断裂韧性 

分 类 号：TG115.54[金属学及工艺—物理冶金]